Does "Int" in C always have the same number of bits as OS bits?

Question

On a system, does the "int" data type in C always have the same number of bits as the OS bits?

Thanks!

Answer 1

No, not necessarily. For an obvious example, if you use a 32-bit compiler on a 64-bit OS, you will usually have 32-bit ints.

The requirements in the C standard are pretty minimal. In addition to the minimum size requirements, there (§6.2.5 / 5):

An object

A '' plain intis the natural size suggested by the runtime architecture (large enough to contain any value in the range from INT_MINto INT_MAX, as defined in the header <limits.h>).

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Answer 2

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• , 2014-02-14, <http://www.cplusplus.com/reference/cstdint/>

Answer 3

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Answer 4

64- Debian

#include <stdio.h>

int main() {
    #define printSize(aType) printf("sizeof " #aType " = %ld\n", sizeof(aType))
    printSize(void*);
    printSize(char);
    printSize(short);
    printSize(int);
    printSize(long);
    printSize(long long);
}

:

sizeof void* = 8
sizeof char = 1
sizeof short = 2
sizeof int = 4
sizeof long = 8
sizeof long long = 8

, int 64 64- , , int . , .

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